Method for determining the harvest time of henna leaves for use as raw materials in the production of Lawson and method for producing henna leaves for use as raw materials in the production of Lawson

Abstract

To provide a method for determining the harvest time of henna leaves for raw material for lawson production that contain a high content of lawson, and to provide a method for producing henna leaves for raw material for lawson production with a high content of lawson.SOLUTION: Provided is a method comprising: (1) starting henna cultivation in an area where the average daily temperature is 0°C or higher; (2) cultivating henna until the tree height is 0.8 m or more; (3) continuing to cultivate henna and measuring an amount of precipitation, temperature, and an amount of solar energy in the area; (4) calculating cumulative precipitation for the most recent 3 months or the most recent 4 months, cumulative average temperature for the most recent 5 or 6 months, and cumulative solar energy for the most recent 6 or 7 months; and (5) determining that it is the appropriate time for harvesting, or harvesting the henna leaves, if the value calculated in (4) above falls under any one of the followings (a) to (f): (a) cumulative precipitation in the last three months being less than 55 mm; (b) cumulative precipitation in the last four months being less than 70 mm; (c) cumulative average temperature over the past 5 months being less than 150°C; (d) cumulative average temperature over the past 6 months being less than 170°C; (e) cumulative solar energy for the most recent 6 months being less than 39 kWh; and (f) the cumulative solar energy for the most recent 7 months being less than 45 kWh.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a method for determining the harvest time of henna leaves for use as raw materials for the production of lawsone, and a method for producing henna leaves for use as raw materials for the production of lawsone. [Background technology]

[0002] Henna (Lawsonia inermis), an evergreen shrub in the Lythraceae family, grows naturally in semi-arid and tropical regions of North Africa, Asia, and northern Australia. It has oval leaves measuring 1.5–5 cm long and 0.5–2 cm wide, and fragrant white or pale pink flowers.

[0003] Lawsone (2-hydroxy-1,4-naphthoquinone), a characteristic component of henna, is a type of naphthoquinone and is also known as a red (orange) pigment. Lawsone has been reported to have various pharmacological activities, including antioxidant and antibacterial properties, and is one of the compounds that may be used as a pharmaceutical seed.

[0004] Powdered henna leaves are called henna dyes and have been used since ancient times in India and other parts of Asia for tattooing during ceremonies and weddings, as well as for treating and preventing cuts, ulcers, and inflammation. In recent years, henna has also been widely used as an ingredient in hair color and hair treatments. It is believed that henna leaves dye hair and skin orange by covalently bonding with nucleophilic functional groups in proteins, but the reaction mechanism is unknown. However, the fact that this reaction occurs at room temperature indicates that lawsone is highly reactive.

[0005] A method using dried and crushed henna leaves and stems has been known as a safe hair dyeing method for humans (Patent Document 1). It has also been reported that henna leaves contain more lawsone than flowers and branches (Non-Patent Document 1). [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-209037 [Non-patent literature]

[0007] [Non-Patent Document 1] Oda Y, Nakashima S, Kondo E, Nakamura S, Yano M, Kubota C, Masumoto Y, Hirao M, Ogawa Y, Matsuda H. J Nat Med. (2018) 72(4): 890-896. Summary of the Invention [Problem to be solved by the invention]

[0008] An object of the present invention is to provide a method for determining the harvest time of henna leaves that are high in lawsone and are used as a raw material for producing lawsone, and a method for producing henna leaves that are high in lawsone and are used as a raw material for producing lawsone. [Means for solving the problem]

[0009] The present invention includes the following inventions to solve the above problems. <1> 1. A method for determining the best time to harvest henna leaves for use in the production of Lawson, comprising: (1) The process of starting henna cultivation in areas where the average daily temperature is above 0°C; (2) Cultivating henna until it reaches a height of 0.8 m or more; (3) continuing to cultivate henna and measuring the amount of rainfall, temperature, and solar energy in the area; (4) calculating the cumulative precipitation for the most recent three months or the most recent four months, the cumulative average temperature for the most recent five months or the most recent six months, and the cumulative solar energy for the most recent six months or the most recent seven months; and (5) A method comprising a step of determining that the time is suitable for harvesting when the value calculated in (4) corresponds to any one of the following (a) to (f): (a) The accumulated precipitation over the last three months is less than 55 mm; (b) Accumulated precipitation over the last four months is less than 70 mm; (c) The cumulative average temperature over the last five months is less than 150°C; (d) The cumulative average temperature for the last six months is less than 170°C; (e) The accumulated solar energy for the last six months is less than 39 kWh; and (f) The accumulated solar energy for the last seven months is less than 45 kWh. <2> A method for producing henna leaves for use as raw materials for producing Lawson, (1) The process of starting henna cultivation in areas where the average daily temperature is above 0°C; (2) Cultivating henna until it reaches a height of 0.8 m or more; (3) continuing to cultivate henna and measuring the amount of rainfall, temperature, and solar energy in the area; (4) calculating the cumulative precipitation for the most recent three months or the most recent four months, the cumulative average temperature for the most recent five months or the most recent six months, and the cumulative solar energy for the most recent six months or the most recent seven months; and (5) A method comprising the step of harvesting henna leaves when the value calculated in (4) corresponds to any one of the following (a) to (f): (a) The accumulated precipitation over the last three months is less than 55 mm; (b) Accumulated precipitation over the last four months is less than 70 mm; (c) The cumulative average temperature over the last five months is less than 150°C; (d) The cumulative average temperature for the last six months is less than 170°C; (e) The accumulated solar energy for the last six months is less than 39 kWh; and (f) The accumulated solar energy for the last seven months is less than 45 kWh. [Effects of the Invention]

[0010] According to the present invention, there are provided a method for determining the harvest time of henna leaves that are high in lawsone and are used as a raw material for producing lawsone, and a method for producing henna leaves that are high in lawsone and are used as a raw material for producing lawsone. DETAILED DESCRIPTION OF THE INVENTION

[0011] The present invention provides a method for determining the appropriate time for harvesting henna leaves for use as a raw material for producing lawsone (hereinafter referred to as the "harvest time determination method of the present invention"). The harvest time determination method of the present invention may include the following steps (1) to (5): (1) The process of starting henna cultivation in areas where the average daily temperature is above 0°C; (2) Cultivating henna until it reaches a height of 0.8 m or more; (3) continuing to cultivate henna and measuring the amount of rainfall, temperature, and solar energy in the area; (4) calculating the cumulative precipitation for the most recent three months or the most recent four months, the cumulative average temperature for the most recent five months or the most recent six months, and the cumulative solar energy for the most recent six months or the most recent seven months; and (5) A method comprising a step of determining that the time is suitable for harvesting when the value calculated in (4) corresponds to any one of the following (a) to (f): (a) The accumulated precipitation over the last three months is less than 55 mm; (b) Accumulated precipitation over the last four months is less than 70 mm; (c) The cumulative average temperature over the last five months is less than 150°C; (d) The cumulative average temperature for the last six months is less than 170°C; (e) The accumulated solar energy for the last six months is less than 39 kWh; and (f) The accumulated solar energy for the last seven months is less than 45 kWh.

[0012] The present invention also provides a method for producing henna leaves for use as raw materials for producing lawsone (hereinafter referred to as "the production method of the present invention"). The production method of the present invention may include the following steps (1) to (5). The production method of the present invention may also be referred to as "a method for harvesting henna leaves for use as raw materials for producing lawsone." (1) The process of starting henna cultivation in areas where the average daily temperature is above 0°C; (2) Cultivating henna until it reaches a height of 0.8 m or more; (3) continuing to cultivate henna and measuring the amount of rainfall, temperature, and solar energy in the area; (4) calculating the cumulative precipitation for the most recent three months or the most recent four months, the cumulative average temperature for the most recent five months or the most recent six months, and the cumulative solar energy for the most recent six months or the most recent seven months; and (5) A method comprising the step of harvesting henna leaves when the value calculated in (4) corresponds to any one of the following (a) to (f): (a) The accumulated precipitation over the last three months is less than 55 mm; (b) Accumulated precipitation over the last four months is less than 70 mm; (c) The cumulative average temperature over the last five months is less than 150°C; (d) The cumulative average temperature for the last six months is less than 170°C; (e) The accumulated solar energy for the last six months is less than 39 kWh; and (f) The accumulated solar energy for the last seven months is less than 45 kWh.

[0013] Hereinafter, the harvest time determination method of the present invention and the production method of the present invention will be collectively referred to as the "method of the present invention."

[0014] Henna (Lawsonia inermis) used in the method of the present invention is a woody plant belonging to the genus Lawsonia in the family Lythraceae. Henna is also called henna, tumbleweed, or finger flower.

[0015] Henna leaves accumulate large amounts of lawsone (2-hydroxy-1,4-naphthoquinone), a compound with the following structure. Lawsone has an affinity with keratin, a protein in hair, and is known to have hair dyeing properties, as well as lowering body temperature, antiseptic properties, hemostatic properties, and medicinal properties for burns, bruises, and dermatitis. [ka]

[0016] In step (1), henna cultivation is initiated in an area where the average daily temperature is 0°C or higher. The average daily temperature in the cultivation area may be 2°C or higher, 4°C or higher, or 6°C or higher. There is no particular upper limit to the average daily temperature, but it may be 43°C or lower, or 40°C or lower. The method of the present invention can be applied to henna grown outdoors.

[0017] In step (1), the method for starting henna cultivation is not particularly limited. For example, seeds may be sown in soil and allowed to germinate, seeds may be germinated on an agar medium or the like and then transplanted into soil, or cultivation may be initiated by vegetative propagation such as by cuttings.

[0018] In step (2), henna is cultivated until it reaches a height of 0.8 m or more. There are no particular limitations on the method for cultivating henna, and it can be cultivated using a method commonly used to cultivate evergreen shrubs. Henna trees eventually reach a height of 3 m or more. When the height reaches 0.8 m or more, it is possible to harvest leaves containing the same amount of lawsone as that contained in the leaves of mature trees with a height of 3 m or more. Step (2) is intended to grow henna until it is time to harvest henna leaves containing lawsone suitable for use as a raw material for lawson production, and step (2) does not necessarily have to end when the tree height reaches 0.8 m. In step (2), the henna may be cultivated until it reaches a height of 0.9 m or more, or until it reaches a height of 1.0 m or more, or even longer.

[0019] In step (3), the cultivation of henna continues, and the amount of precipitation, temperature, and solar energy in the cultivation area are measured. Because henna is an evergreen tree, after the henna has grown to a time suitable for leaf harvesting in step (2), the leaves can be harvested at any time. Therefore, in step (3), measurements of the amount of precipitation, temperature, and solar energy are started in order to carry out the method of the present invention.

[0020] Although there are no particular limitations on the methods for measuring the amount of precipitation, temperature, and amount of solar energy, it is preferable to use methods adopted by government agencies in charge of meteorological affairs in the cultivation region, companies that provide meteorological information for the cultivation region, etc., or methods equivalent thereto. Measurements of the amount of precipitation, temperature, and amount of solar energy are usually carried out daily.

[0021] Measurements of precipitation, temperature, and solar energy are preferably carried out on the farm where henna is grown. However, meteorological data (precipitation, temperature, and solar energy) from the henna-growing region where the method of the present invention is to be carried out may also be obtained and used. For example, meteorological data provided by an administrative agency in charge of meteorological affairs in the growing region (e.g., the Japan Meteorological Agency) may be used, or meteorological data obtained from a company that provides meteorological information services may be used. When using external data, it is preferable to select an administrative agency or company that provides meteorological data from a meteorological observation station closest to the henna-growing region where the method of the present invention is to be carried out. Preferably, meteorological data measured at a meteorological observation station in the same city or town as the henna-growing region where the method of the present invention is to be carried out is used.

[0022] In step (4), the accumulated precipitation for the most recent three months or the most recent four months, the accumulated average temperature for the most recent five months or the most recent six months, and the accumulated solar energy for the most recent six months or the most recent seven months are calculated.

[0023] In step (5), it is confirmed whether the value calculated in step (4) corresponds to one of the following (a) to (f). (a) Accumulated precipitation for the last three months is less than 55 mm (b) Accumulated precipitation over the last four months is less than 70 mm (c) The cumulative average temperature for the last five months is less than 150°C. (d) The cumulative average temperature for the last six months is less than 170°C. (e) The accumulated solar energy for the last six months is less than 39 kWh. (f) The accumulated solar energy for the last seven months is less than 45 kWh.

[0024] In the method for determining the harvest time of the present invention, if the value calculated in step (4) corresponds to any one of the following (a) to (f), it can be determined that the time is suitable for harvesting. In addition, in the production method of the present invention, if the value calculated in step (4) corresponds to any one of the following (a) to (f), henna leaves are harvested.

[0025] It has been confirmed that the lawsone content of henna leaves harvested at a time that satisfies the above-mentioned criteria (a) to (f) is significantly higher than the lawsone content of henna leaves harvested at a time that does not satisfy the criteria (a) to (f) (see Examples). Therefore, by carrying out the method of the present invention, it is possible to efficiently produce lawsone from henna leaves. [Example]

[0026] The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples.

[0027] Example 1: Correlation analysis between lawsone content and cultivation climate 1-1 Henna Cultivation Areas and Henna Leaf Harvesting Henna leaves were harvested from plants over 1.0 m tall at two cultivation sites (Cultivation Site A and Cultivation Site B) in Sojat, Rajasthan, India. Harvesting took place between 2017 and 2019, six times per year in each area, for a total of 18 harvests. Temperatures in Sojat are reported to range from 11°C to 40°C throughout the year, rarely dropping below 8°C or above 43°C (see WeatherSpark).

[0028] 1-2 Measurement of Lawsone Content 1-2-1 Preparation of Lawson standard solution and test solution Approximately 15.0 mg of Lawsone standard (Merck) was accurately weighed and dissolved in mobile phase (3:1 water:acetonitrile, pH 3.0), and the solution was adjusted to exactly 100 mL. The solution was filtered through a Cosmonice filter W (Nacalai Tesque) to prepare the standard solution. Approximately 5.0 g of dried henna leaves (Lot 1: cultivation area A, Lot 2: cultivation area B) were weighed, and 100 mL of mobile phase was added. Extraction was performed at room temperature. The supernatant of the extract was filtered through a Cosmonice filter W, and the filtrate was used as the test solution.

[0029] 1-2-2 Measurement method Using the standard and test solutions prepared as described above, the lawsone content was measured using the apparatus and conditions described in Table 1. [Table 1]

[0030] 1-2-3 Measurement results The lawsone content (mg) per 100 g of each lot sample is shown in Table 2. It was confirmed that the lawsone content in both Lot 1 and Lot 2 increased or decreased depending on the harvest time. [Table 2]

[0031] 1-3 Correlation between weather data and Lawson content 1-3-1 Meteorological data collection and correlation analysis We investigated whether variations in lawsone content due to henna leaf harvest time are related to weather conditions at harvest time. Precipitation, temperature, and solar energy data for Sojat City, a henna-growing region, were collected from WeatherSpark (https: / / weatherspark.com, Cedar Lake Ventures, Inc.), which provides weather data from around the world. Starting from the month prior to the henna leaf harvest month, precipitation, average temperature, and solar energy were back-integrated to calculate accumulated precipitation (mm), accumulated average temperature (°C), or accumulated solar energy (kWh) from 1 month to 11 months prior. Pearson's product-moment correlation coefficients were calculated to determine the correlation between the lawsone content of each sample and each calculated integrated value.

[0032] (1) Correlation with accumulated precipitation The correlation coefficient between the lawsone content of lot 1 and the accumulated precipitation for the 3, 4, 5, and 6 months before the henna leaf harvest was -0.4 or less. The correlation coefficient between the lawsone content of lot 2 and the accumulated precipitation for the 2, 3, 4, 5, 6, 7, and 8 months before the henna leaf harvest was -0.4 or less. Therefore, it was considered that the lawsone content of henna leaves has a weak negative correlation with the accumulated precipitation.

[0033] (2) Correlation with cumulative mean temperature The correlation coefficient between the lawsone content of lot 1 and the accumulated mean temperature for 4, 5, 6, 7, and 8 months before the henna leaf harvest was -0.4 or less. The correlation coefficient between the lawsone content of lot 2 and the accumulated mean temperature for 5, 6, 7, and 8 months before the henna leaf harvest was -0.4 or less. Therefore, it was considered that the lawsone content of henna leaves has a weak negative correlation with the accumulated mean temperature.

[0034] (3) Correlation with cumulative solar energy The correlation coefficient between the lawsone content of lot 1 and the accumulated solar energy 5, 6, 7, 8, and 9 months before harvesting the henna leaves was -0.4 or less. The correlation coefficient between the lawsone content of lot 2 and the accumulated solar energy 6, 7, 8, 9, and 10 months before harvesting the henna leaves was -0.4 or less. Therefore, it was considered that the lawsone content of henna leaves has a weak negative correlation with the accumulated solar energy.

[0035] 1-3-2 Analysis of weather conditions for harvesting high-lawsone henna leaves (1) Accumulated precipitation Using data on the cumulative precipitation for the three and four months prior to henna leaf harvest, we attempted to determine the threshold for harvesting henna leaves with a high lawson content. The lawsone content of Lot 1 and Lot 2 and the cumulative precipitation for the three and four months prior to henna leaf harvest are shown in Table 3.

[0036] [Table 3]

[0037] The henna leaves were divided into two groups: those with accumulated precipitation of less than 55 mm in the three months prior to harvest and those with accumulated precipitation of 55 mm or more. The mean lawsone content was compared using a t-test between the two groups. The henna leaves were also divided into two groups: those with accumulated precipitation of less than 70 mm in the four months prior to harvest and those with accumulated precipitation of 70 mm or more. The mean lawsone content was compared using a t-test between the two groups. As shown in Table 4, significant differences were observed between the two groups for both accumulated precipitation levels. Therefore, it was demonstrated that henna leaves with a high lawson content can be obtained for use as a raw material for lawson production by harvesting henna leaves when accumulated precipitation over the past three months is less than 55 mm or when accumulated precipitation over the past four months is less than 70 mm.

[0038] [Table 4]

[0039] (2) Accumulated average temperature Using data on the cumulative average temperature for the five and six months prior to harvesting henna leaves, we attempted to determine the standard value for harvesting henna leaves with a high lawson content. The lawsone content of Lot 1 and Lot 2 and the cumulative average temperature for the five and six months prior to harvesting henna leaves are shown in Table 5.

[0040] [Table 5]

[0041] The henna leaves were divided into two groups: those with cumulative mean temperatures of less than 150°C and those with temperatures of 150°C or higher over the five months prior to harvest. The mean lawsone content was compared using a t-test between the two groups. The henna leaves were also divided into two groups: those with cumulative mean temperatures of less than 170°C and those with temperatures of 170°C or higher over the six months prior to harvest. The mean lawsone content was compared using a t-test between the two groups. As shown in Table 6, significant differences were observed between the two groups for both cumulative mean temperatures. Therefore, it was demonstrated that henna leaves with a high lawson content can be obtained for use as a raw material for lawson production by harvesting them when the cumulative mean temperature over the previous five months is less than 150°C or when the cumulative mean temperature over the previous six months is less than 170°C.

[0042] [Table 6]

[0043] (3) Accumulated solar energy Using data on the accumulated solar energy six and seven months before harvesting henna leaves, we attempted to determine the standard value at which high-lawsone-containing henna leaves could be harvested. The lawsone content of Lot 1 and Lot 2 and the accumulated solar energy six and seven months before harvesting henna leaves are shown in Table 7.

[0044] [Table 7]

[0045] The henna leaves were divided into two groups: those with accumulated solar energy over the six months prior to harvesting (less than 39 kWh) and those with accumulated solar energy over 39 kWh or more. The average lawsone content was compared using a t-test between the two groups. The henna leaves were also divided into two groups: those with accumulated solar energy over the seven months prior to harvesting (less than 45 kWh) and those with accumulated solar energy over 45 kWh or more. The average lawsone content was compared using a t-test between the two groups. As shown in Table 8, significant differences were observed between the two groups for both accumulated solar energy levels. Therefore, it was demonstrated that henna leaves with a high lawson content can be obtained for use as a raw material for lawson production by harvesting henna leaves when the accumulated solar energy over the past six months is less than 39 kWh or when the accumulated solar energy over the past seven months is less than 45 kWh.

[0046] [Table 8]

[0047] The present invention is not limited to the above-described embodiments and examples, and various modifications are possible within the scope of the claims. The technical scope of the present invention also includes embodiments obtained by appropriately combining the technical means disclosed in different embodiments. Furthermore, all academic literature and patent documents described in this specification are incorporated herein by reference.

Claims

1. 1. A method for determining the best time to harvest henna leaves for use in the production of Lawson, comprising: (1) starting the cultivation of henna in an area where the average daily temperature is 0°C or higher; (2) cultivating the henna plant until it reaches a height of 0.8 m or more; (3) continuing to cultivate henna and measuring the amount of rainfall, temperature, and solar energy in the area; (4) calculating the cumulative precipitation for the most recent three months or the most recent four months, the cumulative average temperature for the most recent five months or the most recent six months, and the cumulative solar energy for the most recent six months or the most recent seven months; and (5) A method comprising a step of determining that the time is suitable for harvesting when the value calculated in (4) corresponds to any one of the following (a) to (f): (a) The cumulative precipitation for the last three months is less than 55 mm; (b) The cumulative precipitation over the last four months is less than 70 mm; (c) The cumulative average temperature for the last five months is less than 150°C; (d) The cumulative average temperature for the last six months is less than 170°C; (e) The accumulated solar energy for the last six months is less than 39 kWh; and (f) The accumulated solar energy for the last seven months is less than 45 kWh.

2. A method for producing henna leaves for use as raw materials for producing Lawson, (1) starting the cultivation of henna in an area where the average daily temperature is 0°C or higher; (2) cultivating the henna plant until it reaches a height of 0.8 m or more; (3) continuing to cultivate henna and measuring the amount of rainfall, temperature, and solar energy in the area; (4) calculating the cumulative precipitation for the most recent three months or the most recent four months, the cumulative average temperature for the most recent five months or the most recent six months, and the cumulative solar energy for the most recent six months or the most recent seven months; and (5) A method comprising the step of harvesting henna leaves when the value calculated in (4) corresponds to any one of the following (a) to (f): (a) The cumulative precipitation for the last three months is less than 55 mm; (b) The cumulative precipitation over the last four months is less than 70 mm; (c) The cumulative average temperature for the last five months is less than 150°C; (d) The cumulative average temperature for the last six months is less than 170°C; (e) The accumulated solar energy for the last six months is less than 39 kWh; and (f) The accumulated solar energy for the last seven months is less than 45 kWh.

Images